A top cover assembly and a battery cell

Abstract

The embodiment of the application provides a top cover assembly and a battery monomer, the top cover assembly comprises a pressure relief valve and a liquid injection hole, and the pressure relief valve and the liquid injection hole are arranged at intervals along the length direction of the top cover assembly. Wherein, along the length direction of the top cover assembly, the distance between the end of the pressure relief valve close to the liquid injection hole and the center of the liquid injection hole is D1, and D1 is greater than or equal to 10mm, so that in the process of pouring electrolyte, the electrolyte overflowing through the liquid injection hole can be reduced to directly flow to the pressure relief valve, and the corrosion of the structure of the pressure relief valve can be avoided to cause damage. That is, by limiting the distance between the pressure relief valve and the liquid injection hole, the physical isolation between the pressure relief valve and the liquid injection hole is realized, the normal work of the pressure relief valve is avoided, and the use safety of the battery monomer is ensured. At the same time, by limiting the distance between the pressure relief valve and the liquid injection hole, the strength and rigidity of the top cover assembly can be avoided to decrease due to stress concentration in the preparation or use process of the top cover assembly, and the use safety of the top cover assembly is affected.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a top cover assembly and a battery cell. Background Technology

[0002] With the rapid development of new energy technologies, batteries are being applied to more and more fields, and people's requirements for battery safety performance are also increasing. A battery cell includes a top cover assembly and a casing. The top cover assembly is equipped with an explosion-proof valve and an electrolyte injection port. When electrolyte is injected through the injection port, splashed electrolyte may cause chemical corrosion to the explosion-proof valve, weakening its strength and affecting its normal operation. This, in turn, affects the safety performance of the battery cell, leading to potential safety hazards. Utility Model Content

[0003] This application provides a top cover assembly and a battery cell to solve the technical problem in the prior art where electrolyte easily corrodes explosion-proof valves.

[0004] In a first aspect, embodiments of this application provide a top cover assembly, the top cover assembly including an explosion-proof valve and an injection hole, the explosion-proof valve and the injection hole being spaced apart along the length direction of the top cover assembly; wherein, along the length direction of the top cover assembly, the distance between the end of the explosion-proof valve near the injection hole and the center of the injection hole is D1, where D1≥10mm.

[0005] In this embodiment, the top cover assembly is provided with an explosion-proof valve and an injection hole, which are spaced apart along the length of the top cover assembly. The distance between the end of the explosion-proof valve closest to the injection hole and the center of the injection hole is D1, and D1 ≥ 10mm. This reduces the risk of electrolyte overflowing through the injection hole and flowing directly to the explosion-proof valve, thus preventing corrosion and damage to the valve's structure. In other words, by limiting the distance between the explosion-proof valve and the injection hole, physical isolation is achieved, reducing the impact of electrolyte overflow on the explosion-proof valve structure and preventing disruption to its normal operation, thereby ensuring the safety of the battery cells. Simultaneously, limiting the distance between the explosion-proof valve and the injection hole prevents stress concentration during the manufacturing or use of the top cover assembly, which could lead to a decrease in strength and rigidity and affect its safety.

[0006] In one specific embodiment, along the thickness direction of the top cover assembly, the injection hole has a first segment and a second segment that are connected, with the first segment located above the second segment; the cross-sectional area of ​​the first segment is larger than the cross-sectional area of ​​the second segment.

[0007] In one specific embodiment, the cross-sectional area of ​​the first segment gradually decreases along the direction from the first segment to the second segment.

[0008] In one specific embodiment, a rounded corner is provided at the connection position between the first segment and the second segment.

[0009] In one specific embodiment, the top cover assembly includes a substrate having a protrusion; along the thickness direction of the top cover assembly, a first segment penetrates a portion of the substrate structure, and a second segment penetrates another portion of the substrate structure and the protrusion.

[0010] In one specific embodiment, along the thickness direction of the top cover assembly, the thickness of the substrate is T1; the depth of the first segment is T2; and the depth of the second segment is T3; wherein, T1 > T3 > T2.

[0011] In one specific embodiment, the diameter of the second segment is D2, the thickness of the substrate is T1, and D2 / T1 satisfies 1≤D2 / T1≤1.75.

[0012] In one specific embodiment, the top cover assembly is further provided with a pole mounting hole; along the length direction of the top cover assembly, the center of the pole mounting hole, the center of the injection hole, and the center of the explosion-proof valve are aligned.

[0013] In one specific embodiment, the electrode mounting holes include a positive electrode mounting hole and a negative electrode mounting hole; along the length direction of the top cover assembly, the distance between the center of the positive electrode mounting hole and the center of the negative electrode mounting hole is D3, the length of the substrate is D4, and D3 / D4 satisfies 0.65≤D3 / D4≤0.75.

[0014] Secondly, embodiments of this application provide a battery cell, the battery cell comprising: a top cover assembly and a housing, the housing having an opening; wherein, the top cover assembly is sealed at the opening; the battery cell further comprises a cell assembly, the cell assembly being housed within the housing.

[0015] In this embodiment, the battery cell includes a top cover assembly and a housing with an opening. The top cover assembly seals the opening of the housing to form a cavity capable of accommodating the cell assembly, electrolyte, and other components. Furthermore, by providing the top cover assembly as described in the above embodiment on the battery cell, during electrolyte filling, it prevents electrolyte from overflowing through the filling hole and flowing directly to the explosion-proof valve, thus avoiding corrosion damage to the explosion-proof valve structure. This ensures the normal operation of the explosion-proof valve and prevents any impact on the safety of the battery cell during subsequent use. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in this application in a specific embodiment;

[0018] Figure 2 for Figure 1 Schematic diagram of the top cover assembly;

[0019] Figure 3 for Figure 2 Cross-sectional view of the substrate;

[0020] Figure 4 for Figure 3 A magnified view of part I in the middle.

[0021] Figure label:

[0022] 1-Battery cell;

[0023] 11-Top cover assembly;

[0024] 111-Explosion-proof valve;

[0025] 112 - Injection Hole;

[0026] 112a - First paragraph;

[0027] 112b - Second paragraph;

[0028] 112c - Rounded corners;

[0029] 113-Substrate;

[0030] 113a - Protrusion;

[0031] 114 - Pole mounting hole;

[0032] 114a - Positive electrode mounting hole;

[0033] 114b - Negative electrode mounting hole;

[0034] 12-Shell. Detailed Implementation

[0035] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0036] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0037] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0038] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0039] With the rapid development of new energy technologies, batteries are being applied to an increasing number of fields, and people's requirements for battery safety performance are also increasing. A battery cell includes a top cover assembly and a casing. The top cover assembly is equipped with an explosion-proof valve and an electrolyte injection port. The explosion-proof valve's function is to relieve pressure and prevent explosions, maintaining the pressure balance inside and outside the battery cell. The electrolyte injection port's function is to fill the casing with electrolyte, and after filling, the injection port is sealed to prevent electrolyte leakage. However, when using the electrolyte injection port for electrolyte filling, splashed electrolyte may cause chemical corrosion to the explosion-proof valve structure, weakening its strength and affecting its normal operation. This, in turn, affects the safety performance of the battery cell, creating a potential safety hazard.

[0040] To solve the above technical problems, such as Figure 1 and Figure 2 As shown, this application embodiment provides a top cover assembly 11 and a battery cell 1 including the top cover assembly 11. The top cover assembly 11 may include an explosion-proof valve 111 and a liquid injection hole 112, which are spaced apart along the length of the top cover assembly 11. Specifically, along the length of the top cover assembly 11, the distance between the end of the explosion-proof valve 111 near the liquid injection hole 112 and the center of the liquid injection hole 112 is D1, where D1 ≥ 10 mm.

[0041] In this embodiment, the top cover assembly 11 is provided with an explosion-proof valve 111 and an injection hole 112, which are spaced apart along the length of the top cover assembly 11. The distance between the end of the explosion-proof valve 111 closest to the injection hole 112 and the center of the injection hole 112 is D1, and D1 ≥ 10 mm. This reduces the risk of electrolyte overflowing through the injection hole 112 and flowing directly to the explosion-proof valve 111, thus preventing corrosion and damage to the structure of the explosion-proof valve 111. In other words, by limiting the distance between the explosion-proof valve 111 and the injection hole 112, physical isolation between them is achieved, reducing the impact of electrolyte overflowing through the injection hole 112 on the structure of the explosion-proof valve 111, avoiding interference with the normal operation of the explosion-proof valve 111, and ensuring the safety of the battery cell 1.

[0042] Meanwhile, by limiting the distance between the explosion-proof valve 111 and the injection hole 112, it is possible to avoid the decrease in strength and rigidity of the top cover assembly 11 due to stress concentration during the preparation or use process, which would affect the safety of the top cover assembly 11.

[0043] Wherein, D1 can be 10mm, 11mm, 12mm, etc. In other embodiments, D1 can also be other values. In this application embodiment, the specific value of D1 is not limited and can be adjusted according to the actual situation.

[0044] like Figure 1 and Figure 2 As shown, the battery cell 1 may include a top cover assembly 11 and a housing 12, the housing 12 having an opening, wherein the top cover assembly 11 is sealed at the opening. The battery cell 1 also includes a cell assembly, which is housed within the housing 12.

[0045] In this embodiment, the battery cell 1 includes a top cover assembly 11 and a housing 12 with an opening. The top cover assembly 11 is used to seal the opening of the housing 12 to form a cavity (not shown in the figure) capable of accommodating the cell assembly, electrolyte, and other components. Furthermore, by providing the top cover assembly 11 as described in the above embodiment on the battery cell 1, during electrolyte filling, it is possible to prevent the electrolyte from overflowing through the injection hole 112 and flowing directly to the explosion-proof valve 111, thus avoiding corrosion damage to the explosion-proof valve structure. This ensures the normal operation of the explosion-proof valve 111 and prevents it from affecting the safety of the battery cell 1 during subsequent use.

[0046] In one specific embodiment, such as Figures 2 to 4 As shown, along the thickness direction of the top cover assembly 11, the injection hole 112 may have a first segment 112a and a second segment 112b that are connected. The first segment 112a is located above the second segment 112b, and the cross-sectional area of ​​the first segment 112a is larger than the cross-sectional area of ​​the second segment 112b.

[0047] In this embodiment, the injection hole 112 is designed as a stepped hole with a first segment 112a and a second segment 112b that are connected. The first segment 112a is located above the second segment 112b, meaning the first segment 112a is located away from the housing, while the second segment 112b is located close to the housing. After the electrolyte is injected, a sealing structure (not shown in the figure) needs to be provided in the injection hole 112 to achieve a sealing effect. The cross-sectional area of ​​the second segment 112b is made smaller so that the second segment 112b, located close to the housing, can form an interference fit with the steel ball or sealing particles in the sealing structure, improving the sealing effect on the electrolyte. At the same time, the cross-sectional area of ​​the first segment 112a, located away from the housing, is made larger to facilitate the installation of the snap-on sealing cap or rubber plug in the sealing structure, thereby improving the connection reliability between the sealing structure and the injection hole 112 as a whole. The larger cross-sectional area of ​​the first segment 112a also facilitates the subsequent disassembly or replacement of the sealing structure.

[0048] In one specific embodiment, such as Figure 2 and Figure 4 As shown, along the direction from the first segment 112a to the second segment 112b, the cross-sectional area of ​​the first segment 112a can gradually decrease.

[0049] In this embodiment, the cross-sectional area of ​​the first segment 112a gradually decreases along the direction from the first segment 112a to the second segment 112b. This facilitates the installation of the first segment 112a with the sealing structure, providing a guiding effect for the installation of the sealing structure and improving the reliability of the connection between the sealing structure and the first segment 112a. This prevents detachment during use, which could lead to electrolyte leakage and affect the safety of the battery cell. Simultaneously, the gradual reduction in the cross-sectional area of ​​the first segment 112a causes its inner wall to slope along the direction from the first segment 112a to the second segment 112b. When electrolyte is injected through the injection hole 112, this reduces the amount of electrolyte remaining on the inner wall of the first segment 112a. The electrolyte is guided by the sloped inner wall of the first segment 112a and flows back into the casing, further reducing the risk of electrolyte overflow during the filling process and minimizing its impact on other components of the top cover assembly 11.

[0050] In one specific embodiment, such as Figure 2 and Figure 4 As shown, a rounded corner 112c can be provided at the connection position between the first segment 112a and the second segment 112b.

[0051] In this embodiment, by providing a fillet 112c at the connection point of the first segment 112a and the second segment 112b, the stress concentration effect at the connection point can be reduced, extending the service life. Furthermore, since the cross-sectional areas of the first segment 112a and the second segment 112b are different, the injection hole 112 has a stepped hole structure. Providing a fillet 112c at the connection point can prevent damage to the sealing structure during installation, thus avoiding affecting the sealing effect on the electrolyte. Additionally, providing a fillet 112c at the connection point can improve the smoothness of the connection, facilitating the installation of the sealing structure.

[0052] In addition, by setting a rounded corner 112c at the connection, the flow path of the electrolyte can be optimized, avoiding turbulence or splashing during electrolyte filling caused by sharp transitions at the connection, reducing the risk of electrolyte overflow, further reducing the impact of electrolyte overflow on structures such as the explosion-proof valve 111, and improving the safety of the battery cell.

[0053] The radius of the fillet 112c can be between 0.1mm and 0.5mm. For example, the radius of the fillet 112c can be 0.1mm, 0.3mm, 0.5mm, etc. This satisfies the usage requirements of the injection hole 112 while avoiding processing difficulties and increased manufacturing costs due to the radius of the fillet 112c being too large or too small. In other embodiments, the radius of the fillet 112c can also be other values. In this application embodiment, the radius of the fillet 112c is not specifically limited and can be adaptively adjusted according to the actual situation.

[0054] In one specific embodiment, such as Figure 2 and Figure 4 As shown, the top cover assembly 11 may include a substrate 113, which may be provided with a protrusion 113a. Along the thickness direction of the top cover assembly 11, a first segment 112a penetrates a portion of the substrate 113 structure, and a second segment 112b penetrates another portion of the substrate 113 structure and the protrusion 113a.

[0055] In this embodiment, the substrate 113 is provided with a protrusion 113a, and along the thickness direction of the top cover assembly 11, the first segment 112a penetrates a portion of the substrate 113 structure, and the second segment 112b penetrates another portion of the substrate 113 structure and the protrusion 113a. While ensuring the strength of the substrate 113, the depth of the first segment 112a and the second segment 112b can be increased to increase the contact area between the first segment 112a and the second segment 112b and the sealing structure, thereby improving the sealing effect of the sealing structure on the liquid injection hole 112 as a whole and improving the connection stability between the two.

[0056] In one specific embodiment, such as Figure 2 and Figure 4As shown, along the thickness direction of the top cover assembly 11, the thickness of the substrate 113 can be T1, the depth of the first segment 112a can be T2, and the depth of the second segment 112b can be T3, where T1 > T3 > T2.

[0057] In this embodiment, the injection hole 112 has a stepped hole structure, with the first segment 112a located above the second segment 112b. Therefore, the second segment 112b, closer to the housing, has a greater depth, increasing the contact area between the second segment 112b and the sealing particles in the sealing structure. This improves the connection reliability between the sealing particles and the second segment 112b, further enhancing the sealing effect and preventing electrolyte leakage. Simultaneously, the shallower depth of the first segment 112a above the second segment 112b facilitates the installation of the sealing sheet in the sealing structure, improving the overall connection reliability between the sealing structure and the injection hole 112. Furthermore, the sealing sheet in the sealing structure is connected to the top cover assembly 11 by welding. The greater depth of the second segment 112b also reduces the impact of welding heat generated during the welding process on the sealing particles, ensuring the effectiveness of the sealing particles.

[0058] In addition, the thickness of the substrate 113 is made greater than the depth of the first segment 112a and the second segment 112b to ensure that the strength and rigidity of the substrate 113 meet the usage requirements and extend the service life of the substrate 113.

[0059] In one specific embodiment, such as Figure 2 and Figure 4 As shown, the diameter of the second segment 112b can be D2, and the thickness of the substrate 113 can be T1, where D2 / T1 satisfies 1≤D2 / T1≤1.75.

[0060] In this embodiment, the second segment 112b is disposed on the substrate 113, such that the diameter D2 of the second segment 112b and the thickness T1 of the substrate 113 satisfy 1≤D2 / T1≤1.75. For example, D2 / T1 can be 1, 1.5, 1.75, etc. This avoids affecting the overall rigidity of the substrate 113 due to the excessively large diameter of the second segment 112b, thereby ensuring the safety of the top cover assembly 11. At the same time, it also avoids affecting the filling efficiency of the electrolyte filling hole 112 due to the excessively small diameter of the second segment 112b, and also avoids making subsequent sealing structure assembly difficult and reducing the overall assembly rate of the battery cell due to the excessively small diameter of the second segment 112b.

[0061] In other embodiments, D2 / T1 can also be other values. In this application embodiment, the specific value of D2 / T1 is not limited and can be adjusted adaptively according to the actual situation.

[0062] In one specific embodiment, such as Figure 2As shown, the top cover assembly 11 may also be provided with a pole mounting hole 114, and the center of the pole mounting hole 114, the center of the injection hole 112 and the center of the explosion-proof valve 111 are aligned along the length of the top cover assembly 11.

[0063] In this embodiment, the centers of the terminal mounting holes 114, the liquid injection holes 112, and the explosion-proof valve 111 in the top cover assembly 11 are aligned along the length of the top cover assembly 11. This avoids localized stress concentration during the manufacturing or use of the top cover assembly 11 and prevents deformation of these components due to uneven stress during stamping or welding caused by misalignment of the centers of the terminal mounting holes 114, the liquid injection holes 112, and the explosion-proof valve 111. This ensures the safety of the battery cell. Therefore, coaxial arrangement of the terminal mounting holes 114, the liquid injection holes 112, and the explosion-proof valve 111 in the top cover assembly 11 results in a more balanced stress distribution, improves the overall rigidity of the top cover assembly 11, and enhances its safety during use.

[0064] In one specific embodiment, such as Figure 2 and Figure 3 As shown, the electrode mounting hole 114 may include a positive electrode mounting hole 114a and a negative electrode mounting hole 114b. Along the length direction of the top cover assembly 11, the distance between the center of the positive electrode mounting hole 114a and the center of the negative electrode mounting hole 114b is D3, and the length of the substrate 113 is D4. D3 / D4 satisfies 0.65≤D3 / D4≤0.75.

[0065] In this embodiment, D3 / D4 is set to 0.65 ≤ D3 / D4 ≤ 0.75. For example, D3 / D4 can be 0.65, 0.70, 0.75, etc. This avoids stress concentration on the substrate 113 due to an excessively small distance between the center of the positive terminal mounting hole 114a and the center of the negative terminal mounting hole 114b, which could easily cause the substrate 113 to break and affect the safety of the battery cell. Simultaneously, it also avoids an excessively large distance between the center of the positive terminal mounting hole 114a and the center of the negative terminal mounting hole 114b, which could limit the current carrying capacity of the battery cell and easily lead to increased temperature rise during charging and discharging, causing thermal runaway.

[0066] In other embodiments, D3 / D4 can also be other values. In this application embodiment, the specific value of D3 / D4 is not limited and can be adjusted adaptively according to the actual situation.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A top cover assembly, characterized in that, The top cover assembly (11) includes an explosion-proof valve (111) and a liquid injection hole (112), and the explosion-proof valve (111) and the liquid injection hole (112) are spaced apart along the length direction of the top cover assembly (11); Wherein, along the length direction of the top cover assembly (11), the distance between the end of the explosion-proof valve (111) near the injection hole (112) and the center of the injection hole (112) is D1, where D1≥10mm.

2. The top cover assembly according to claim 1, characterized in that, Along the thickness direction of the top cover assembly (11), the injection hole (112) has a first section (112a) and a second section (112b) that are connected, with the first section (112a) located above the second section (112b); The cross-sectional area of ​​the first segment (112a) is greater than the cross-sectional area of ​​the second segment (112b).

3. The top cover assembly according to claim 2, characterized in that, Along the direction from the first segment (112a) to the second segment (112b), the cross-sectional area of ​​the first segment (112a) gradually decreases.

4. The top cover assembly according to claim 2, characterized in that, The first segment (112a) and the second segment (112b) are connected by a rounded corner (112c).

5. The top cover assembly according to claim 2, characterized in that, The top cover assembly (11) includes a substrate (113) having a protrusion (113a); Along the thickness direction of the top cover assembly (11), the first segment (112a) penetrates a portion of the substrate (113) structure, and the second segment (112b) penetrates another portion of the substrate (113) structure and the protrusion (113a).

6. The top cover assembly according to claim 5, characterized in that, Along the thickness direction of the top cover assembly (11), the thickness of the substrate (113) is T1; the depth of the first segment (112a) is T2; and the depth of the second segment (112b) is T3. Among them, T1 > T3 > T2.

7. The top cover assembly according to claim 6, characterized in that, The diameter of the second segment (112b) is D2, and the thickness of the substrate (113) is T1, where D2 / T1 satisfies 1≤D2 / T1≤1.

75.

8. The top cover assembly according to any one of claims 1-7, characterized in that, The top cover assembly (11) is also provided with pole mounting holes (114); Along the length of the top cover assembly (11), the center of the pole mounting hole (114), the center of the injection hole (112), and the center of the explosion-proof valve (111) are aligned.

9. The top cover assembly according to claim 8, characterized in that, The electrode mounting hole (114) includes a positive electrode mounting hole (114a) and a negative electrode mounting hole (114b); the top cover assembly (11) includes a substrate (113); Along the length direction of the top cover assembly (11), the distance between the center of the positive electrode mounting hole (114a) and the center of the negative electrode mounting hole (114b) is D3, and the length of the substrate (113) is D4, where D3 / D4 satisfies 0.65≤D3 / D4≤0.

75.

10. A single battery cell, characterized in that, The battery cell (1) includes: Top cover assembly (11), wherein the top cover assembly (11) is the top cover assembly (11) according to any one of claims 1-9; A housing (12) having an opening; The top cover assembly (11) is sealed at the opening; the battery cell (1) also includes a cell assembly, which is housed within the housing (12).

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